Field of the Invention
The present invention relates to an assembly structure of a drive shaft and a hub bearing, and more particularly, to an apparatus for transferring driving force at a wheel for a vehicle capable of increasing load capacity of the hub bearing by unifying a housing of a constant velocity joint and a hub flange to be coupled to each other and reinforcing stiffness of the coupled portion.
Description of Related Art
In general, a drive shaft is an apparatus for transferring power generated from a power train to a wheel, a transmission and the wheels are each provided with a joint, and particularly, a ball joint is mainly used in the wheel side to transfer the power by reflecting a bent angle upon steering.
FIG. 1 is a view for describing a configuration in which a drive shaft is assembled in the wheel side according to the related art, wherein a hub bearing 2 is provided to the wheel side, an inner race 2a of the hub bearing 2 is coupled to the wheel, a housing 1 of a constant velocity joint is inserted to penetrate through a center of the inner race 2a, and a fixing nut 3 is fastened to an end of the housing 1 protruded through the center of the inner race 2a, thereby fixing the inner race and housing in a state in which a relative rotation is restricted.
However, in the coupling structure according to the related art described above, a setting of a final preload for the bearing is completed after assembling the constant velocity joint, wherein the preload may be unevenly applied due to tightening torque of the fixing nut during a process of fastening the fixing nut, and axial force loss of the bearing may also be generated as shown by an arrow.
In addition, since the inner race and the housing are fixed to each other by using the fixing nut as described above, it is also disadvantageous in view of production cost/weight of a vehicle and productivity according to an increase in the number of parts.
In addition, since the end of the inner race and a housing portion facing the end of the inner race are fastened in a state in which they contact each other, a joint may be generated by a stick-slip phenomenon on the contacting surface.
Meanwhile, according to the related art, Korean Patent Laid-Open Publication No. 10-2005-0022565 entitled “A Wheel bearing without Shaft Washer” has been disclosed.
However, even by the above-mentioned method, since a wheel mounting flange supporting the hub bearing and the constant velocity joint housing are fastened by the fixing nut, the problems according to the related art described above caused by the fixing nut fastening method may not be solved.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the present invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.